BRASILIA, Brazil — Ordering a major military strike is a daunting task for any American president. Doing it between diplomatic and economic meetings in a foreign capital over 4,000 miles from Washington is even more complex.

President Barack Obama faced that situation Saturday as he juggled the pageantry and substance attendant to his first South American visit with urgent phone calls and top-level national security consultations about a pending joint aerial assault against Libya.

Before touching down in Brazil, according to the White House, Obama got an important intelligence briefing on Air Force One: forces loyal to Libyan leader Muammar Qadhafi were advancing on the opposition-held city of Benghazi despite a United Nations resolution allowing use of force to stop it — and the regime’s own dubious claims that they had halted action against the rebels.

After striding down the stairs of the presidential aircraft with first lady Michelle Obama and daughters Malia and Sasha, Obama headed to his quarters in a Brasilia hotel, where he received another briefing and spoke briefly with the crown prince of the United Arab Emirates, the White House said. Then, it was on to review the ceremonial guard at the Brazilian presidential palace and meet with President Dilma Vana Rousseff.

A joint statement with Rousseff, however, fell more than an hour behind schedule — largely because Obama joined a secure call about the Libyan situation with Defense Secretary Robert Gates and Joint Chiefs of Staff Chairman Adm. Mike Mullen. Secretary of State Hillary Clinton, also on the call, briefed the group about international talks she attended in Paris on Saturday about enforcing the U.N. resolution.

“At every juncture where it was necessary for the president to engage in discussions with his national security team….we’ve carved out that time,” Deputy National Security Adviser Ben Rhodes told White House reporters during a conference call Saturday evening. “We’ve pushed back our schedule on multiple occasions today because the president wanted to make sure he had time be fully briefed up and pass his guidance on to the team.”

After the first fusillade of U.S. cruise missiles slammed into Libyan air defense installations just after 3 P.M. Eastern time, Obama headed to a scheduled meeting with Brazilian and American business executives. But he also managed to squeeze in an unscheduled statement to the media about the attack.

“Today, I authorized the Armed Forces of the United States to begin a limited military action in Libya in support of an international effort to protect Libyan civilians,” the president said, speaking at the convention center where he had just met with business leaders. “That action has now begun.”

Because there was short notice before he spoke, U.S. networks were unable to broadcast Obama’s statement live, but ABC News aired it as it happened through an audio-only telecom feed.

While the frenetic pace of calls, meetings and ceremonies clearly demonstrates Obama’s ability to multitask, the White House descriptions of the president’s day also intended to address questions that emerged just before the president’s departure — particularly, why he would take a less-than-urgent Latin America tour amidst a bloody government crackdown in Libya and a Japanese nuclear plant, crippled in a devastating earthquake, on the brink of a full-scale meltdown.

As the president prepared for the trip in recent days, the White House was surprisingly adamant that it would go forward. Rhodes again insisted Saturday the president’s five-day trip — scheduled to take him next to Rio and then on to Santiago, Chile, and San Salvador, El Salvador — is unlikely to be curtailed, despite crisis-level world events.

“We have no plans to cut the trip short,” he declared.

However, Rhodes freely acknowledged that military actions against Libya became accelerated largely due to “forces that were moving toward Benghazi,” which has been widely reported as the the poorly-trained, lightly-armed rebels’ last stand. Qadhafi, who came to power in a military coup, had vowed to show no mercy in his assault on the town, which analysts said would effectively crush the three-week-old uprising and preserve his 40-year rule.

Despite a broad U.N. resolution to use all necessary force against the regime to stop the slaughter of civilians, there were signs that the allied military campaign, unfolding in the Mediterranean Sea and in the skies over Libya, was hastily assembled.

Aircraft from France, which had strongly advocated for force against Qadhafi, began bombing selected government targets in the middle of the day Saturday, a move that reportedly upset some coalition members. While Clinton emphasized that the U.S. “did not lead” the assault, Pentagon officials said American military power is at the vanguard of the campaign’s early stages, although commanders planned to scale it back to a support role as the action continued.

“We are on the leading edge of coalition operations,” Vice Adm. William Gortney said in a briefing Saturday, adding that upwards of 110 missiles had been launched against Libya.

In addition, Pentagon officials said that the American forces involved were not yet under a coordinated, international command. For now, U.S. missions are being directed by Admiral Sam Locklear, commander of the Navy’s Africa forces, aboard the Mediterranean-based fleet command ship USS Mount Whitney.

While Obama’s foreign travels may not have impeded his ability to act as commander in chief, the timing of the Libyan strikes did put his Brazilian hosts in something of an awkward position.

Brazil was among five countries that abstained from voting Thursday on the United Nations Security Council resolution, and its diplomats made clear their nation viewed military action as unwise and counterproductive. On Saturday, Brazilian leftists, angered by U.S. involvement in actions against Libya, protested Obama’s visit and clashed with police.

However, the sequence of events that the White House laid out in painstaking detail makes clear that Obama was intimately engaged in directing the U.S. military campaign from Brazilian soil — making his hosts unwitting participants in the international use of force against Qadhafi.